1. Field of the Invention
The present invention relates to high brightness, high power laser diode systems.
2. Description of Related Art
In the field of high power laser diodes, certain applications are limited by the available brightness emitted by laser diodes. The available brightness may be limited by spatial and spectral brightness distributions.
Spatial brightness is typically optical power divided by spatial angle (beam divergence) and focused spot size. It is desirable to have low divergence beams for many applications, including coupling the beams into fiber optics. Spectral brightness is the width of the spectral band of the beam. In many applications it is desirable to produce beams with relatively narrow spectral bands, for controlled interaction with the target of the beam. In other applications, the wider spectral bands are acceptable.
To reach high brightness levels, outputs of multiple laser diodes have been used. One technology for combining beams from multiple diode lasers is described in U.S. Pat. No. RE40,173 titled “High Efficiency, High Power, Direct Diode Laser Systems and Methods Therefor” by Mark Zediker, et al. However, large arrays of laser diode sources needed to achieve high output powers for combined beams present practical issues with use of beam combiners of the prior art. For example, because of the need to mount such large arrays in configurations that allow for efficient delivery of power, effective cooling and for low cost manufacturing, blocks of fiber coupled, laser diodes have been developed. The fiber coupling however reduces beam quality, and therefore the efficiency of the beam combining technologies.